- Cap: 2-4.5 cm broad, convex, becoming nearly plane with a low umbo; margin striate, often wavy, sometimes upturned in age; surface smooth, sticky when moist, hygrophanous, brown, fading to yellow-brown or buff; flesh thin, brittle in age, bruising blue.
- Spore print: Purple-brown to purple-gray or purple-black; Spores 9-12 x 6-8 µm, elliptical, smooth, with an apical pore; spore print purple-brown to purple-grey.
- Bruising: blue or blue-green
- Gills: adnate to seceding, close when young, subdistant in age, pale cinnamon brown, becoming dark grey-brown, edges lighter than the faces, mottled from spores at maturity.
- Stipe: 3-6 cm tall, 3-6 mm thick, equal to sometimes enlarged at the base, the latter with conspicuous thickened mycelium (rhizomorphs); surface white, smooth to silky, bruising blue; veil fibrillose, forming a superior, evanescent hairy, annular zone.
- Veil: absent
Water-soaked hardwood chips, available in hardware stores as chips for smoking fish and game.
Water-soaked corrugated cardboard.
Fresh chipped hardwood.
Temperature 45-65 F
Psilocybe cyanescens are widely scattered to densely gregarious on woodchips, sawdust, mulch, and humus, and on lawns rich in lignin; partial to coniferous debris, but fond of alder and eucalyptus. It is fairly common in the San Francisco Bay Area in cold weather (mainly December and January, though in favorable conditions fruiting as late as March),especially in landscaped areas and mulched flower beds, and is also fairly common in Oregon, Washington, and British Columbia. The season in the Pacific Northwest is earlier and more brief than in California, typically September and October only.